While speaking on Tuesday, November 8, at the inauguration of Edo State University, Iyamho, in Etsako West local government area of the state, the President said that multi-party system is the best option for the country's democracy.
Buhari also noted that Nigeria became a mono-economy after "throwing away everything for petroleum."
"We believe in multi-party democracy system, it is the best for us. In a country of over 450 ethnic groups, it is not easy to come together, only God can do it," he said.
"We are doing our best because we have found ourselves as part of this great country called Nigeria."
The President was in the state for a two-day state visit.
He urged Nigerians to see the current economic recession in the country as an opportunity to diversify the economy for sustainable growth.
He said: "We are blessed with human and material resources. We made terrible mistakes in allowing ourselves to become a mono-economy and we are now paying dearly for our mistakes.
"Nigeria made money from cocoa, palm oil, palm kernel, groundnut, hides and skin and others. We threw everything away because of petroleum.
"We have to go back to the land and solid minerals and do a lot of savings so that we can leave a better country for our children."
Buhari thanked Nigerians for their cooperation and faint in his administration to reform the country.